The general objective of the project is to synthesize a variety of medicinal compounds which have been identified by the Developmental Therapeutics Program for development, preclinical toxicology and phase 1 clinical trial. These compounds are not readily available in the quality and quantity needed from the original supplier or on the open market. The laboratories are used to obtain data for the preparation of the necessary quantities of clinically important chemicals and to develop the most economical means for their preparation. Many methods of synthesis which are practical for small quantities are not technically feasible or economically practical when used for large-scale synthesis operation. The conversion of small-scale production often requires development work which is carried out by these contractors. The preparation laboratories provide the means of obtaining nearly any type of chemical compound in large quantities. The materials are of very high purity and are well characterized. The quantity of a given material synthesized may range from fifty grams to 5 kilograms. Factors governing the amounts needed include the rate of usage, ease of preparation, chemical stability, and cost. Compounds received from these contractors are prepared under current Good Manufacturing Practices and are intended for Preclinical Toxicology, and Phase I Clinical Studies.